How to pass a variable in `redirect(url_for())`

Question

I am trying to pass a variable while redirecting to another URL, with flask, in python, and am getting name var not defined.

This is what Im doing:

@app.route('/')
def root():
    delay = randint(0, 5)
    time.sleep(delay)
    return redirect(url_for('first_hop', delay=delay))

This seems to be the way to pass the variable, based on other answers.

@app.route('/first_hop')
def first_hop():
    x = delay
    print(delay)
    return redirect(url_for('second_hop'))

But here, I don't know how to get it. Do I have to make the variable global?

The error is below.

NameError: name 'delay' is not defined

Possible duplicate of How can I pass arguments into redirect(url_for()) of Flask? — CaptainDaVinci
– CaptainDaVinci, Commented Nov 7, 2019 at 18:32

CaptainDaVinci · Accepted Answer · 2019-11-07 18:33:58Z

1

In first_hop, the parameters can be obtained using request.args.get('delay').

@app.route('/first_hop')
def first_hop():
    x = request.args.get('delay')
    print(x)
    return redirect(url_for('second_hop'))

answered Nov 7, 2019 at 18:33

CaptainDaVinci

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1 Comment

thank you! I had checked this answer: stackoverflow.com/questions/17057191/…, which didn't work.